111591881 has 2 divisors, whose sum is σ = 111591882. Its totient is φ = 111591880.

The previous prime is 111591863. The next prime is 111591901. The reversal of 111591881 is 188195111.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59521225 + 52070656 = 7715^2 + 7216^2 .

It is a cyclic number.

It is not a de Polignac number, because 111591881 - 2⁶ = 111591817 is a prime.

It is a super-2 number, since 2×111591881² = 24905495810236322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (111591811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55795940 + 55795941.

It is an arithmetic number, because the mean of its divisors is an integer number (55795941).

Almost surely, 2^111591881 is an apocalyptic number.

It is an amenable number.

111591881 is a deficient number, since it is larger than the sum of its proper divisors (1).

111591881 is an equidigital number, since it uses as much as digits as its factorization.

111591881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 35.

The square root of 111591881 is about 10563.7058364951. The cubic root of 111591881 is about 481.4422492486.

The spelling of 111591881 in words is "one hundred eleven million, five hundred ninety-one thousand, eight hundred eighty-one".